signData

Signs data with Schnorr BIP-340 signature.

This is the main entry point for transaction signing.

Process:

1. Create SigningKey from private key (32 bytes)

2. Sign data using Schnorr BIP-340

3. Free SigningKey memory

4. Return 64-byte signature

Usage Example:

val privateKey: ByteArray = hdWallet.selectAccount(0)
    .selectRole(MidnightKeyRole.NIGHT_EXTERNAL)
    .deriveKeysAt(0)
    .privateKey

val transactionData = intent.serialize() // Midnight Intent bytes
val signature = TransactionSigner.signData(privateKey, transactionData)

// signature is 64 bytes: [R (32 bytes) || s (32 bytes)]

Signature Format:

• 64 bytes total

• First 32 bytes: R (public nonce commitment)

• Last 32 bytes: s (signature scalar)

• Conforms to BIP-340 standard

Parameters

Throws